Hey Ito, What is the deal with the clearance tolerances? I mean to ask on a 60k mile 13B-rew that had collant seal failure is there a typical one to keep an eye out for that will get out of wack whe reassembling the short block?

I am refering more to the eshaft play and the bearings more that the corner seals and side seals.

How much attention to detail really needs to be paid here?

Check out the updated FAQ at the top of the screen.



There is a site just for you https://www.nopistons.com/forums/pub...DIR#>/moon.gif

i have a question about the apex seal the groove clearance

its supposed to be 0.0027-0.003" with a max of 0.004" every other fd motor we take apart is at 0.004" or more, they seem to run ok that way so how important is that clearance?



mike

Yea I have been through that site man. I was trying to get some discussion going on..

I like chatting more than just reading.

belie' dat!

Let's get a discussion going. Ask me what exactly you want to know and Ill try to give you some input on my experiences and great results on clearancing.

well we notice on say stock to mildly modded fd's that the apex seal grooves are in a v shape (particularly the corners), and that when you measure it its out of spec. how evever they seem to run fine with used (out of spec) rotors, what do think judge?



mike

I find it better to have a bit more clearance in the apex seal to rotor groove,then not enough. I have seen the V shape on the rotors by the corner seal also, but if measured deeper into the rotor groove the fit starts to get tighter.(basically, there's a tighter fit in the bottom of the groove and a wider fit at the top of the groove, I measure at the bottom of the groove) When I install the apex seal into the rotor groove, I make sure the apex seal is well in the groove, then I start to run my gauge well into the botton of the groove and get an even clearance from one point of the rotor to the other point. Considering metal expands under heat, is always good to extra clearance this areas a bit more. For that reason sometimes using rotors with a bit out of clearance will not hurt the engine but could prematurely hurt the apex seals from to much flapping back and forth in the excessive groove clearance from the rotors having to much V groove(clearance) by the corner seals. Let's keep this topic flowing. FD3Boost where are you? https://www.nopistons.com/forums/pub...IR#>/boink.gif

hmm so you mean if its even it should be ok? do you ever hammer the corners back? i like this kinda topic, i dont build that many motors



mike

Yes a nice even clearance from one side of the rotor to the other side. No hammering the corner seals, they should fit nice and tight but no hammering.